Mix chilli powder, garlic powder, grated chocolate, cinnamon, cumin, salt, cayenne pepper, allspice, cloves and bay leaf together in a bowl until seasoning mix is well combined.
Heat olive oil in a casserole pot over medium heat; cook and stir onions and green pepper until lightly browned, about 10 minutes. Add vegetable stock and lentils; simmer for 20 minutes. Stir in seasoning mix, tomato passata, apple cider vinegar and vegan Worcester sauce; simmer for 1 hour more, adding water if chilli gets too thick.
Remove bay leaf from chilli. Blend some of the lentils if you prefer a thinner consistency.